Table 2.

Summary of randomized controlled trials for evaluating the efficacy of therapeutic medial branch blocks.

Study	Study Design	Participants	Interventions	Outcome Measurement	Summary of Outcomes
Manchikanti et al. 2001 [110]	Randomized controlled trial	n = 73 (32 in group I and 41 in group II)	Group I with local anesthetic and Sarapin. Group II with local anesthetic, Sarapin, and methyl prednisolone.	Pain relief, physical health, psychological status, narcotic intake, and employment status at 1, 3, 6, 12,18, 24, and 32 months.	Relief from one to three injections decreased with time, with the highest relief in the first 3 months. The treatment showed significant improvements in overall health status, including pain relief, physical, functional, and psychological status, as well as the ability to return to work. In conclusion, medial branch blocks with local anesthetic and Sarapin, with or without steroids, proved to be a cost-effective and beneficial treatment option for improving pain status, physical and psychological well-being, functional status, and the ability to return to work.
Manchikanti et al. 2007 [111]	Randomized controlled trial	n = 60 (four treatment groups with 15 participants each)	Group I with bupivacaine only. Group II with bupivacaine and Sarapin. Group III with bupivacaine and steroids. Group IV with bupivacaine, Sarapin, and steroids.	NRS, ODI, opioid intake, and employment status at 3, 6, and 12 months.	Significant pain relief and functional improvement were observed at 3, 6, and 12 months. No significant difference was found between steroid and non-steroid treatment groups. The treatment of lumbar facet joint nerve block using local anesthesia, with or without Sarapin or steroids, may be effective for chronic lower back pain originating from the facet joint.

NRS: numeric rating scale, ODI: Oswestry disability index.